Azure Web App on Linux - server patching

Question

We are looking at using web app on linux and just want to get the basics on the PAAS implementation.

This appears to be tricky as the underlying infra is docker, which is immutable. Which makes me think unlike App Service on Windows, the server patching is up to us?

However, we seem to blur this immutability by allowing git pushing of source code, so maybe the docker container is just the baseline image? if so, how does failover/rollover work if the underlying instance is having issues?

So does Azure patch the linux servers for us? if the is answer is 'that depends', when are we on our own?

Answer 1

Microsoft say that they do patch the servers for you.

See the following from https://azure.microsoft.com/en-us/blog/making-it-easier-to-bring-your-linux-based-web-apps-to-azure-app-service/ (Bold is mine)

A great example in the managed platform realm is Azure App Service. Azure App Service provides an easy way to bring source code or containers and deploy full web apps in minutes, with the ease of configuration settings at the hands of the app owner. Built in features such as secure sockets layer (SSL) certificates, custom domains, auto-scaling, setting up a continuous integration and deployment (CI/CD) pipeline, diagnostics, troubleshooting, and much more, provides a powerful platform for full cycle build and management of the applications. Azure App Service also abstracts all of the infrastructure and its management overhead away from the users, maintaining the physical hardware running the service, patching security vulnerabilities, and continuously updating the underlying operating system.

Your question specifically mentions docker containers. See later on in the same page. (Bold is mine)

and one of the most popular options that we've seen on the Linux offering – custom docker containers . Running a container hosted in Azure App Service provides an easy on-ramp for customers wanting to enjoy a fully managed platform , but also want a single deployable artifact containing an app and all of its dependencies, or want to work with a custom framework or version beyond the defaults built into the Azure App Service platform.